Decoding apparatus for digital communications and method for using the same

• US 8,850,294 B1
• Filed: 04/09/2007
• Issued: 09/30/2014
• Est. Priority Date: 04/09/2007
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Zhidkov, Sergey, Rhee, Do-jun
• Primary Examiner(s): Torres, Joseph D
• Application Number:
  US11/733,003
• Time in Patent Office: 2,731 Days
• Field of Search: 714/755, 714/780, 714/794, 714/795
• US Class Current: 714/780
• CPC Class Codes: H03M 13/2936 comprising an outer Reed-Solomon code and an inner convolutional code
• CPC Class Codes: H03M 13/2957 Turbo codes and decoding
• CPC Class Codes: H03M 13/3738 with judging correct decoding
• CPC Class Codes: H03M 13/3776 using a re-encoding step during the decoding process
• CPC Class Codes: H03M 13/618 Shortening and extension of codes

Abstract

A decoding apparatus and method for estimating a reliability value by detecting uncorrected packet errors. The decoding apparatus includes a hard-decision unit and a reliability determination unit. The hard-decision unit performs hard-decision on a soft-input of a code. The reliability determination unit generates a reliability estimation value of the hard-decision result according to whether a packet error exists in the hard-decision result. The hard-decision unit performs hard-decision in response to the reliability estimation value.

Claims

1. A decoding apparatus comprising:

a hard-decision unit performing hard-decision on a soft-input of a code;

a reliability determination unit generating a reliability estimation value of a result of the hard-decision,

wherein the reliability estimation value depends on whether a packet error exists or does not exist in the hard-decision result,

wherein the hard-decision unit performs hard-decision depending on the reliability estimation value,

wherein the reliability determination unit generates the reliability estimation value, which changes depending on the hard-decision result, when the packet error does not exist in the hard-decision result, and the reliability determination unit generates a constant reliability estimation value when the packet error exists in the hard-decision result,

wherein the reliability determination unit comprises a packet error detector for detecting the packet error, depending on the hard-decision result outputted from the hard-decision unit,

wherein the reliability determination unit further comprises a reliability estimation value generator for generating the reliability estimation value of the hard-decision result, according to whether the packet error is detected, and

wherein the reliability estimation value generator further comprises a multiplexer for selecting either the hard-decision result value or a predetermined constant value, depending on whether the packet error is detected.

2. The decoding apparatus of claim 1, wherein the reliability estimation value is fed back to the hard-decision unit.

3. The decoding apparatus of claim 1, wherein the hard-decision unit comprises a hard-decision Reed-Solomon decoder for performing the hard-decision and outputting the hard-decision result to the reliability determination unit.

4. The decoding apparatus of claim 3, wherein the hard-decision unit further comprises a soft-input/hard-output decoder for generating a hard-output, depending on the soft-input of the code and the reliability estimation value, and

the hard-decision Reed-Solomon decoder performs the hard-decision on the hard-output generated by the soft-input/hard-output decoder.

5. The decoding apparatus of claim 4, wherein the soft-input/hard-output decoder is a soft-input/hard-output Viterbi decoder or a soft-input/hard-output convolutional decoder.

6. The decoding apparatus of claim 5, further comprising:

a deinterleaver deinterleaving the hard-output of the soft-input/hard-output decoder and outputting a deinterleaved result to the hard-decision Reed-Solomon decoder; and

an interleaver interleaving the reliability estimation value of the reliability determination unit and outputting the interleaved result to the soft-input/hard-output decoder.

7. The decoding apparatus of claim 6, wherein the soft-input/hard-output Viterbi decoder uses an output value of the interleaver to calculate a branch matrix.

8. The decoding apparatus of claim 1, wherein the reliability estimation value generator generates the reliability estimation value, which changes depending on the hard-decision result, when no packet error is detected, and

the reliability estimation value generator generates a constant reliability estimation value when the packet error is detected.

9. The decoding apparatus of claim 8, wherein, when no packet error is detected, the reliability estimation value generator generates a reliability estimation value having a value of +α

, when the hard-decision result is 1, and generates a reliability estimation value of −

α

, when the hard-decision result is 0.

10. The decoding apparatus of claim 8, wherein, when the packet error is detected, the reliability estimation value generator generates a reliability estimation value of 0.

11. The decoding apparatus of claim 1, wherein the code is a concatenated code.

12. A decoding system comprising:

a plurality of decoding apparatuses, each being a decoding apparatus according to claim 1, connected in series;

a plurality of delay units connected in series for sequentially delaying the soft-input, there being one less delay unit than decoding apparatus and all but a first decoding apparatus having a corresponding delay unit;

wherein each of the plurality of delaying units sequentially delays the soft-input and applies the delayed soft-input to the corresponding decoding apparatus; and

each decoding apparatus except the first decoding apparatus performs hard-decision on the received delayed soft-input in response to a reliability estimation value of a hard-decision result output from its immediately previous decoding apparatus.

13. The decoding apparatus of claim 1, wherein the reliability estimation value is either a value based on a hard-decision result value or a predetermined constant value, depending on whether the packet error exists in the hard-decision result.

14. A decoding method comprising:

performing hard-decision on a soft-input of a code; and

generating a reliability estimation value of a result of the hard-decision, wherein the reliability estimation value depends on whether a packet error exists or does not exist in the hard-decision result,

wherein the hard-decision is performed depending on the reliability estimation value, and

wherein the reliability estimation value, which changes depending on the hard-decision result, is generated when the packet error does not exist in the hard-decision result, and a constant reliability estimation value is generated when the packet error exists in the hard-decision result,

wherein generating the reliability estimation value comprises detecting the packet error depending on the hard-decision result,

wherein generating the reliability estimation value further comprises generating a reliability estimation value of the hard-decision result depending on whether the packet error is detected, and

wherein the reliability determination operation further comprises selecting either the hard-decision result value or a predetermined constant value, depending on whether the packet error is detected.

15. The decoding method of claim 14, wherein performing the hard-decision further comprises performing hard-decision Reed-Solomon decoding.

16. The decoding method of claim 15, wherein the hard-decision operation further comprises generating a hard-output depending on the soft-input of the code and the reliability estimation value, and

wherein, in the hard-decision Reed-Solomon decoding operation, the hard-decision is performed on the hard-output generated by a soft-input/hard-output decoding operation.

17. The decoding method of claim 16, wherein, in the soft-input/hard-output decoding operation, soft-input/hard-output Viterbi decoding is performed.

18. The decoding method of claim 14, wherein, in the generating of the reliability estimation value,

a reliability estimation value, which changes depending on the hard-decision result, is generated when no packet error is detected, and

a constant reliability estimation value is generated when the packet error is detected.

19. The decoding method of claim 18, wherein, in the generating of the reliability estimation value,

when no packet error is detected, a reliability estimation value of +α

is generated when the hard-decision result is 1, and a reliability estimation value of −

α

is generated when the hard-decision result is 0.

20. The decoding method of claim 18, wherein, in the generating of the reliability estimation value, when the packet error is detected, a reliability estimation value of 0 is generated.

21. The decoding method of claim 14, wherein the reliability estimation value is either a value based on a hard-decision result value or a predetermined constant value, depending on whether the packet error exists in the hard-decision result.